Fluorescent labeling of N-glycans is beneficial to detecting glycans because it improves both sensitivity and selectivity of the detection as well as the chromatographic behavior of glycans. Amino acid analysis is a fundamental process in protein research and is of particular importance to clinical chemists and pharmaceutical manufacturers when glycosylation profiling of proteins must be monitored to ensure consistency of a therapeutic product. Upon derivation with a reagent having a fluorescent moiety, the functional group of the compound can only be estimated. Mass spectrometry (“MS”) is then required to identify the specific compound.
Analysis by MS has reached a high degree of development with respect to glycan and amino acid analysis and proteomics. However, the necessary reaction time to functionalize most amines is slow. The current state of the art utilizes tagging molecules that either (1) react quickly and have good fluorescence signal, but poor MS signal or (2) react very slowly and give good MS/fluorescence signals. A combination of MS and fluorescence detection is desirable, however, because fluorescence detection is very useful tool in determining quantitatively how much is present. On the other hand, MS is used to determine what the molecular makeup is.
A need exists, therefore, for molecules with that rapidly react with biomolecules and provide strong mass spectrometry and fluorescence signals.